Gage for edged tools.



H. J. HJORTH.

GAGE FOR EDGED TO0LS.

APPLICATION HLED MAR. 31, 1909.

"1,174,009; Patented Feb. 29, 1916;

wifneasess 1100671507 I rm: COLUMBIA PLANOaRAPl-l c0., WASHINGTON, D. c.

HEN-RY J. HJ'ORTH, OF CAMBRIDGE, MASSACHUSETTS.

GAGE FOR EDGED TOOLS.

S ecification of Letters Patent. P t ted Feb. 29, 1916.

Application filed March 31, 1909. Serial No. 486,890. i

To all whom it may concern Be it known that I, HENRY J. HJORTH, of Cambridge, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Gages for Edged Tools, of which the following is a specification.

The present invention relates to a gage by which the angles and positions of the cutting edges of edged tools may be tested after the tools have been ground.

It has particular reference to twist drills, and the present embodiment of the invention is particularly designed for testing the cutting edges of tools of this character, but it is obvious that the gage is not necessarily restricted to any readily modified so as to be capable of wider application, or may be used with other tools without modification.

The object of the invention is-to provide a gage having means for locating the body or shank of the tool in'a certain definite relation, and having a member so arranged as to be. in position for ready comparison with the cutting edges of the tool so that it may be readily determined whether the edges are correctly ground or not.

Of the accompanying drawings, Figure 1 represents a plan view of a gage embodying the principles of my invention. Fig. 2 represents asimilar view of a modification of such a gage. Fig. 3 represents an elevation of the gage shown in Fig. 2. Fig. 4 represents a sectional view on line 4-4 of Fig. 2, looking in the direction of the arrow. V

The same reference characters indicate the same parts in all the figures.

T he essential features of the gage are a body or shank 1 having. a longitudinal groove 2 in its upper surface, and a gage member or plate 3 in such relation .to the groove that the cutting edges of the tool being tested will be brought adjacent. the gage elements of the plate 3 when the shank or body of thetool is placed in the groove 2. The groove is preferably formed with plane sides 4 and 5 which are inclined toward one another and intersect in a straight line, thereby making a dihedral angle with one another, so that any tool having a shank or body which is circular in cross-section, when placed in the groove such use, but may be in contact with both surfaces 4 and'5', will be located in a position in which its axis coincides with a plane bisecting such angle.

Thegage member or plate 3 is mounted on an extension of the body, which is an arm 6 or neck springing from one side of the shank or body 1 and extending on a curve to a termination at a d stance from, and in line with, one end of the shank, thus formingan extension of the tool-holding part of the gage body. The plate has gaging elements 7 and 8, which, in theembodiment of the invention here shown, are the sides of a notch 9 in th end of the plate which extends toward the shank 1. This plate ismounted on the end of arm 6 and'is so located that the apex of the notch lies in the imaginary central or bisecting plane of the groove, and vi the sides 7 and 8 o angles with said plane, and its own plane is perpendicular to such central plane' and parallel to the apex of the dihedral angle The gage plate is constructed so that it said notch make equal maybe adjustable in the direction of such central or bisecting plane and transverse to the length of the shank 1, in orderthat the apex of its notch may be located in linewith the axes of tools of different-sizes. For this reason the plate is made substantially U-shape, having a central portion 10 contained in a guideway 11,1whch for purposes of description I may term a gage plate guide,

formed in the outer side of the arm 6. and" having its ends bent over toward the shank 1 above and below the arm respectively.

The central part 10 of the plate is retained by a holding screw 12 which is threaded into the arm. Between the head of the screw and the plate is a bowed spring washer l3-which' yieldingly'on the gage plate, holding presses it in contact with the arm without looseness, but permitting it to be adjusted. For adjusting the plate there is provided a screw 14 which. is threaded into a lug 15 0n the arm and enters a notch 16 in the under end 17 of the plate. 18 and 19 embracing the end of the plate so Preferably the collar 19 is a sleeve independently mounted on the shank of the screw adjacent to the head 20. of the screw Thisscrew has collars that it may be moved in 'eitherdirection.

and pressed. against the plate by a spring 21. By means of the spring, looseness between the. plate and collars is taken up and at the same time a friction provided which guards against accidental displacement of the screw from its adjustment.

From Fig. 3, which showsa drill 22 in position on the gage shank, it will be noted that the adjustment above described enables the gage plate to be moved so that the end 8 having the notch may be brought into the plane of the axis of the dri l so that the sides 7 and 8 of the notch will lie beside the cutting edges of the drill. If these edges are correctly ground, they will coincide with the elements 7' and 8, but if the grinding is not correct, there will be a divergence from these elements, which will indicate the degree of imperfection, and enablethe error to be corrected. 7

The only difference between Fig. 1 and the remaining figures is that in the former, the extension or arm 6 is made as an integral part of the shank 1', while in the latter the arm is adjustable longitudinally of the shank. To permit such adjustment, the shank has a lateral support 24 and the arnr lies upon said support, having the slot 25 to receive a clamping screw 26 which is threaded into the support. This screw permits an adjustment of the arm in a manner readily understood, and causes it to be held in place when adjusted. A guideway is formed in the support 24, so that the gage plate may not accidentally be displaced out of alinement with the groove.

It is evident that many variations in the form of the groove 2 and of the gage plate 3 may be made within the scope of my invention, as defined in the following claims.

I claim Y 1. A gage of the character described, comprising a body having surfaces making a dihedral angle with one another and forming a tool-centering groove, said body having an extension from the tool-holding part thereof provided witha gage plate guide extending in the same direction as a plane bisecting the said dihedral angle, a gage plate lying in a plane perpendicular to such bisecting plane and parallel with the apex of the angle and having a notch of which the apex lies-in such bisecting plane, said plate also having a portion engaged with said guide and held thereby so that displacement of the notch in its own plane is prevented, and means for adjusting the plate along the guide. 7 1

2. A gage of the character described, comprisinga shank or body having a longitudinal groove formed by intersecting plane surfaces, an-arm extending, from beside said shank to a point in line with the end thereof, a bent plate having its central portion held against said arm, one of the ends of said plate being formed with a notch extending toward the shank and located symmetrically with respect to the groove, and an adjusting device engaged with said arm and with a part of the plate, whereby the notched end thereof may be adjusted transversely of the shank.

3. A gage of the character described, comprising a shank orbodyhaving a longitudinal groove formed by intersecting plane I surfaces, an arm extending from beside said shank to a point in line with the end thereof, a plate having its ends bent over at right angles to its central part, one of such ends having'a notch and the central part being engaged with said arm in such a manner that the notched end extends toward the shank in line with the groove therein, and an adjusting screw threaded into the arm and engaged with the other end of said plate.

4;. A gage of the character described, comprising a shank or body having a longitudinal groove formed bv intersecting plane surfaces, an arm extending from beside said shank to a point in line with the end'thereof and having a guideway extending transversely with respect to said shank,-a plate contained in said guideway, a screw passing adjacent to the plate into the arm, a spring between the head of said screw and plate for clamping the latter yieldinglv against the arm, one end of the plate being bent over toward the shank and having a notch centrally located with respect to the groove therein, the other end of said plate being also bent over and lying beneath the arm. andan adjusting screw threaded into the arm and engaged with this end of the plate for adjusting the plate in the guideway.

5. A gage of the character described, com prising a shank or body having a longitudinal groove formed bv intersecting'plane surfaces, an arm extending from beside said shank to a point in line with the end thereof and being adjustable longitudinally of the shank, a plate having one end bent to extend toward the shank and provided with a notch in line with the groo've. said plate being mounted adjustably on said arm, and

means for adjusting the plate'transversely of the arm and shank. 1

In testimony whereof I have ai'lixed my signature, in presence of two witnesses.

HENRY J. HJ-ORTH.

WVitnesses:

ELIZABETH M. Bnn'rson, Cnannns F. REMINGTON.

Copies of this. patent may be obtained for five cents each, by addressing the Commissioner of Patents.

' WashingtomDC." 

